Reduced fat sour cream

ABSTRACT

The present invention provides sour cream formulated with microparticulated protein which serves as a replacement for all or part of the fat and/or oil normally found in sour cream.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of our copending U.S. patent application Ser. No. 07/367,261 filed June 16, 1989, which issued as U.S. Letters Pat. No. 4,961,953 on Oct. 9, 1990, which is a continuation of our U.S. patent application Ser. No. 07/127,955, filed Dec. 2, 1987, now abandoned, which, in turn, was a continuation-in-part of our U.S. patent application Ser. No. 06/606,959 filed May 4, 1984, which issued as U.S. Letters Pat. No. 4,734,287 on Mar. 29, 1988.

BACKGROUND

The present invention relates to reduced fat sour cream compositions which include a microparticulated protein product as described in our allowed U.S. Pat. No. 4,961,953, the entire disclosure of which is incorportated by reference herein.

SUMMARY OF THE INVENTION

The present invention is a reduced fat sour cream having all or part of the fat and/or oil content normally found in sour cream replaced with a proteinaceous, water-dispersible, macrocolloid comprising substantially non-aggregated particles of denatured protein having in a dry state a mean diameter particle size distribution ranging from about 0.1 to about 2.0 microns, with less than about 2 percent of the total number of particles exceeding 3.0 microns in diameter, and wherein the majority of the said particles are generally spheroidal as viewed at about 800 power magnification under a standard light microscope, the particles in a hydrated state form said macrocolloid having substantially smooth, emulsion-like organoleptic character.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a photomicrographic view at 1000x magnification of a sample of microparticulated whey protein according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following examples relate to preferred methods and procedures for practicing the present invention. Example 1 relates to a preferred method for the production of microparticulated protein from the proteinaceous material present in acidified whey. Example 2 relates to a preferred method for the production of microparticulated protein from casein micelles and the proteinaceous material present in egg white. Example 3 relates to the production of microparticulated protein from the proteinaceous material in whey. Example 4 relates to the preparation of a reduced fat sour cream. Example 5 relates to the preparation of a flavored reduced fat sour cream dip.

EXAMPLE 1 Microparticulated Protein Produced from Acidified Whey

Microbiologically, aromatically and particulately clean water produced by a reverse osmosis process is added to a sanitary tank.

Commercially available liquid whey protein concentrate is treated by ultrafiltration and evaporation until the concentration of protein is about 50-55% by weight, on a dry basis. The whey protein concentrate is added to the water in the sanitary tank with agitation avoiding aeration through the suction side of a positive displacement pump to achieve a solids concentration of about 37% solids for the mixture.

As this mixture is recirculated back to the sanitary tank, a dilute solution of food acid (acetic, lactic, citric or hydrochloric: alone or in combination) is added through an in-line mixer to lower the pH from about 6.8 to about 4.4±0.05.

The pH adjusted mixture is then rigorously deaerated in a Versator deaerator/homogenizer and bottom fed into a holding tank which is equipped for non-aerating agitation.

The deaerated mix is then pumped (300 lbs/hr) from the holding tank, by a positive displacement pump through an in-line strainer (300 μm cheesecloth) and a mass flow meter, into a plate heat exchanger which heats the mixture to about 165°-180° F., a temperature lower than the target peak temperature which is achieved within a heat and shear generating apparatus ("microcooker"). Flow is manually-controlled based on readings from the in-line flow-meter.

The heated mixture is pumped directly from the plate heat exchanger into the microcooker apparatus as described in U.S. Pat. No. 4,823,396 with the exception that the inlet and outlet ports have been interchanged or exchanged, i.e., the inlet port is disposed where the outlet port is shown in the patent drawing and the outlet port is located at the bottom of the bowl shaped vessel and the temperature of the mixture is raised to about 200° F. within less than 10 seconds under high shear conditions. Rigorous temperature control of the mixture is maintained at 200° F. by means of a cascade control loop. The control loop senses the temperature of the product exiting the microcooker and maintains it at 200° F. by adjusting the temperature of the mixture leaving the plate heat exchanger.

The speed of the rotor in the microcooker is held constant, for example, at about 3715 rpm. At this rpm, the shear rate is about 27,000 reciprocal seconds at the tips of the rotor which has a diameter of approximately 7 inches.

After exiting the microcooker apparatus, the product flows directly into an eccentric scraped surface heat exchange and is cooled with vigorous agitation to less than 130° F. The cooled product then flows through additional heat exchangers (scraped surface of plate type) to reduce its temperature to less than 55° F.

EXAMPLE 2 Microparticulated Protein Produced from Casein Micelles and Egg White

Microbiologically, aromatically and particulately clean water (16.83 wt. %) produced by a reverse osmosis process is heated in a sanitary tank to about 120° F.

Commercially available apple pectin (0.35 wt. %) dry-blended with sugar (5.0 wt. %) to assure its complete dispersion and is then added to the water in the sanitary tank by means of a high shear solid/liquid Triblender mixer. This mixture is held at about 120°-140° F. with agitation for about 5 minutes to assure hydration and dissolution of the pectin. The mixture is then cooled to less than about 100° F.

Liquid egg white is ultrafiltered using membrane filters having a molecular weight cut-off of about 10,000. The ultrafiltration reduces the total volume of the liquid egg white by about 50% and effectively doubles the protein content and halves the sodium content of the egg white. The treated egg white (55 wt. %) is added to the pectin solution through the suction side of a positive displacement pump with controlled agitation to avoid aeration.

Condensed skim milk (22 65 wt. %) is then added to the mixture through the suction side of a positive displacement pump.

As this mixture is recirculated back to the sanitary tank, a dilute solution of food acid (0.17 wt. %) (acetic, citric, lactic or nydrochloric; alone or in combination) is added through an in-line mixer to lower the pH from about 7 to about 6.20±0.05.

The pH adjusted mix is then rigorously deaerated in a Versator deaerator and bottom-fed into a holding tank which is equipped for non-aerating agitation.

The deaerated mixture is then pumped (600 lb/hr) from the holding tank, by a positive displacement pump through an in-line strainer (300 μm cheesecloth) and a mass flow meter into a plate heat exchanger which heats the mixture to about 165° F., a temperature lower than the target peak temperature which is achieved within the microcooker apparatus described in Example 1. At this lower temperature no coagulate will have developed. Flow is manually-controlled based upon readings from the in-line flow-meter.

The heated mixture is pumped directly from the plate heat exchanger into the microcooker apparatus and the temperature of the mixture is raised to about 185° F. within less than about 10 seconds under high sheer conditions. Rigorous temperature control is maintained over the temperature of the mixture in the microcooker apparatus by a cascade control loop. The control loop senses the temperature of a product exiting the microcooker and holds the temperature constant by regulating the temperature of the mixture leaving the plate heat exchanger.

The speed of the rotor in the microcooker is held constant at about 5400 rpm. At this rpm, the shear rate is about 40,000 reciprocal seconds at the tips of the rotor which has a diameter of approximately 7 inches.

After exiting the microcooker apparatus, the product flows directly into an eccentric scraped surface heat exchanger and is cooled with vigorous agitation to less than 130° F. The cooled product then flows through additional heat exchangers (scraped surface or plate type) to reduce its temperature to less than 55° F.

EXAMPLE 3 Microparticulated Protein Produced from Whey

Commercially available liquid whey is treated by ultrafiltration and evaporation to give a mixture having about 42% by weight solids and about 50%-55% by weight protein, on a dry basis. The resulting whey protein concentrate is deaerated in a Versator deaerator and bottom fed into a sanitary tank equipped for a non-aerating agitation.

The deaerated mixture is then pumped (600 lbs/hr), by a positive displacement pump through an in-line strainer (300 μm cheesecloth), a mass flow meter and plate heat exchanger which raises the temperature of the mixture to about 170° F., into a heated holding device.

The heated holding device includes two concentric scraped surface heat exchangers connected in series. Each heat exchanger provides a hold time of about 3.6 minutes at a flow rate of about 300 lbs/hr. Both of these heat exchangers are heated to maintain the hold temperature set by the plate heat exchanger.

The mixture is then pumped from the holding device to an eccentric scraped surface heat exchanger. This scraped surface heat exchanger cools the mixture to a temperature of about 165° F., a temperature lower than the target peak temperature inside a heat and high shear generating apparatus (microcooker). The mixture then flows directly into the microcooker apparatus as described in Example 1 and the temperature of the mixture is raised to 200° F. within 10 seconds under high shear conditions. Rigorous temperature control at 200° F. is maintained in the microcooker by a cascade control loop. The control loop senses the temperature of a product exiting the microcooker and holds the temperature constant by regulation the temperature of the mixture leaving the eccentric scraped surface heat exchanger.

The speed of the rotor in the microcooker is held constant at about 5200 rpm. At this rpm, the shear rate is about 40,000 reciprocal seconds at the tips of the rotor which has a diameter of approximately 7 inches.

After exiting the microcooker apparatus, the product flows directly into an eccentric scraped surface heat exchanger and is cooled with vigorous agitation to less than 130° F. The cooled product then flows through an additional heat exchanger (scraped surface or plate type) to reduce its temperature to less than 55° F.

EXAMPLE 4 Preparation of a Reduced Fat Sour Cream

A reduced fat sour cream was produced from the ingredients listed in Table 1.

                  TABLE 1                                                          ______________________________________                                         Reduced Fat Sour Cream                                                         Ingredients           Wt. % of Composition                                     ______________________________________                                         Ultrafiltered Skim Milk (3×)                                                                   51.4                                                     Cream (14% Butterfat) 6.6                                                      Nonfat Dry Milk       5.4                                                      Microparticulated Protein                                                                            10.0                                                     (Example 3)                                                                    Gelatin               0.2                                                      Sodium Citrate        0.1                                                      Starter System Culture                                                                               0.01                                                     (FARGO 300 starter culture, Microlife)                                         Rennet                0.0015                                                   Flavor                0.15                                                     Antimicrobial         as needed                                                Water                 26.1                                                     ______________________________________                                    

The ultrafiltered skim milk, nonfat dry milk, cream, gelatin, sodium citrate, antimicrobial (if needed), and water were blended and homogenized in a single stage at 2500 psi. The homogenized mixture was heated to about 185° F. for about 10-30 minutes. The microparticulated protein was added to the hot mixture, the temperature was maintained at 185° F. for about 30 seconds, and then the temperature was lowered to about 70°-78° F. The starter system culture, rennet and flavor were added to the system and the mixture was incubated at about 70°-78° F. for about 12-22 hours to a pH of 4.6-4.8. After incubation, the mixture was cooled to about 40°-65° F., pumped through an in-line screen to smooth the product and packaged.

EXAMPLE 5 Preparation of a Flavored Reduced Fat Sour Cream Dip

A flavored reduced fat sour cream dip is prepared by mixing Lipton dry onion soup mix (1 package) with the reduced fat sour cream (8 oz.) prepared according to the procedures described in Example 4. The mixture is stirred well and stored in a refrigerator until used.

Numerous modifications and variations in practice of the invention are expected to occur to those skilled in the art upon consideration of the foregoing descriptions of preferred embodiments thereof. Consequently, only such limitations should be placed upon the scope of the invention as appear in the appended claims. 

What is claimed is:
 1. A reduced fat sour cream, wherein the improvement comprises replacing all or part of the normal fat and/or oil content of the sour cream with a proteinaceous, water-dispersible, macrocolloid comprising substantially non-aggregated particles of denatured protein having in a dry state a mean diameter particle size distribution ranging from about 0.1 microns to about 2.0 microns, with less than about 2 percent of the total number of particles exceeding 3.0 microns in diameter, and wherein the majority of the said particles are generally spheroidal as viewed at about 800 power magnification under a standard light microscope, the particles in a hydrated state form said macrocolloid having substantially smooth, emulsion-like organoleptic character. 